Code section 1245 (or thereabouts) deals with recapture.
Any business asset on which depreciation is taken (allowed or allowable!) must recapture depreciation of any sort upon sale of the asset. See form 4797.
A totaled vehicle would be considered a business casualty loss and the insurance proceeds would be deemed the sales price. It makes no difference whether you purchased the vehicle or financed it and the insurance proceeds were sent to the legal owner. And, remember it is depreciation allowed (i.e., actually deducted from your tax return) or allowable (i.e., you did not take a depreciation deduction but could have). So, you could easily have some recapture in this situation. Or you might have a 1231 loss if the adjusted basis > the insurance proceeds.
I have not had any personal dealings with Lemon Law repurchases for business clients. I do not know how the statute is worded. If you are seriously considering a Lemon Law pursuit, I would consult with your lawyer to determine how the statute reads. It may very well be that a Lemon Law claim voids the purchase contract. If that were the case, I would not take any depreciation on the vehicle, including amending a prior year's return to eliminate the deduction. But I would have to give this more thought than a simple five-minute typed reply in an area that I have not researched.
So, i've think i understand the depreciating portion of purchasing a model X for business use.
Can someone explain the recapture portion if i were to sell the X at some point before 6 years?
You can probably avoid the recapture by trading in the vehicle against a like asset rather than doing an outright sale. Trade-ins also reduce the Sales Tax on the new vehicle in most States. In some States, like PA, you get the reduction in Sales Tax even if the new vehicle is pre-owned. I think the new vehicle will have to be more expensive than the trade-in value in order to avoid the recapture.
I would not hang my hat on trading in vehicles to avoid recapture of depreciation. The New! and Improved! Tax Law specifically eliminated like-kind exchanges for personal property. Apologies for getting technical, but this is an important income tax concept:
In taxation when an asset is sold or disposed of at a gain, this is considered a "realized" gain. However, this gain may not necessarily be "recognized" on one's tax return. Under the old rules, a vehicle trade-in would qualify under the like-kind exchange deferral rules, so the realized gain would not be recognized. Any realized gain so deferred on the trade-in would be used to reduce the basis in the new vehicle acquired. The statute and regulations for section 1031 are written using these terms.
Since these rules have been repealed, I would expect that any automobile trade-in would result in depreciation recapture.